Load cell weighing and drift detection in a electronic scale system

Abstract

Microprocessor for a scale system for a mobile storage carrier operates in three states: motion, stable, and fault where stability is determined based on load cell signal variations or external sources and a fault state follows a stable state in response to signal drift in one or more load cells.

We claim: 
     
         1 . A scale system for a mobile storage carrier comprising:
 a plurality of load cells operatively combined to the mobile storage carrier with each one of the plurality of load cells for detecting deformations in the mobile storage carrier corresponding to weight added or subtracted from the storage carrier, and each one of the plurality of load cells providing an analog output signal;   a multi-channel analog to digital converter (ADC), wherein each one of the plurality of load cells is communicatively coupled to one channel of the multi-channel ADC for converting the analog output signal to a digital output signal;   a microprocessor communicatively coupled to the multi-channel ADC to receive the digital output signal from each channel of the multi-channel ADC, wherein the microprocessor comprises the following states:   a motion state in which the mobile storage carrier is in motion;   a stable state in which the mobile storage carrier is not in motion; and   a fault state in which the mobile storage carrier is in a rest state and a drift greater than a threshold value is measured in at least one load cell of the plurality of load cells.   
     
     
         2 . The scale system of  claim 1 , wherein the microprocessor determines a rest state based solely on variations in measurements of the plurality of load cells. 
     
     
         3 . The scale system of  claim 2 , wherein the plurality of load cells equals n, and wherein the microprocessor determines the rest state when the analog output signal from x number of n load cells fluctuate below a threshold value. 
     
     
         4 . The scale system of  claim 3 , wherein n/2≤x≥n−1. 
     
     
         5 . The scale system of  claim 4 , wherein x=n−1. 
     
     
         6 . The scale system of  claim 1 , wherein the microprocessor determines a rest state based on a signal from a source external to the scale system. 
     
     
         7 . The scale system of  claim 6 , wherein the source external to the scale system is one chosen from a gps, velocity sensor, accelerometer, and a vehicle signal. 
     
     
         8 . The scale system of  claim 1 , and further comprising an artificial intelligence (AI) module configured to collect and analyze date from the microprocessor, which data corresponds to the digital output signals from each of the plurality of load cells, when the microprocessor is in the stable state. 
     
     
         9 . The scale system of  claim 8 , wherein when the microprocessor is in the fault state, the AI module is configured to generate and provide the microprocessor with a simulated signal to replace the digital output signal from one load cell of the plurality of load cells determined to be malfunctioning. 
     
     
         10 . A method for detecting load cell faults in a scale system for a mobile storage carrier, the method comprising:
 receiving, by a multi-channel analog-to-digital converter (ADC), an analog output signal from each of a plurality of load cells operatively combined with the mobile storage carrier;   converting, by the multi-channel ADC, each analog output signal to a corresponding digital output signal;   receiving, by a microprocessor communicatively coupled to the multi-channel ADC, the digital output signal from each of the plurality of load cells;   determining, by the microprocessor, whether the digital output signal from each of the plurality of load cells is stable, and, if so, entering a stable state, and, if not, entering a motion state inferring to the mobile storage carrier being in motion; and   transitioning, by the microprocessor, to a fault state following the stable state in response to determining by the microprocessor that the digital output signal of at least one of the plurality of load cells has a drift greater than a threshold.   
     
     
         11 . The method of  claim 10 , wherein determining whether the mobile storage carrier is in the stable state is based solely on variations in measurements from the plurality of load cells. 
     
     
         12 . The method of  claim 11 , wherein the plurality of load cells equals n, and wherein the microprocessor determines the stable state when the digital output signals from x load cells fluctuate below a predefined threshold, wherein n/2<x<n−1. 
     
     
         13 . The method of  claim 12 , wherein x=n−1. 
     
     
         14 . The method of  claim 10 , further comprising determining the stable state based on a signal from a source external to the scale system. 
     
     
         15 . The method of  claim 14 , wherein the external source is selected from a GPS module, velocity sensor, accelerometer, or a vehicle system signal. 
     
     
         16 . The method of  claim 10 , further comprising: collecting and analyzing, by an artificial intelligence (AI) module, data from the microprocessor corresponding to the digital output signals of each of the plurality of load cells when the microprocessor is in the stable state. 
     
     
         17 . The method of  claim 16 , further comprising: generating, by the AI module, a simulated signal to replace the digital output signal from a malfunctioning load cell when the microprocessor is in the fault state; providing, by the AI module, the simulated signal to the microprocessor to enable continued weight measurement despite a detected load cell failure. 
     
     
         18 . A scale controller communicatively couplable to a plurality of load cells on a mobile storage, the scale controller comprising:
 a motion state based on fluctuating signals from the plurality of load cells;   a stable state based on stable signals from a sufficient number of the plurality of load cells, wherein fluctuating signals from the remaining load cells of the plurality of load cells is indicative of a malfunction in the remaining load cells; and   a fault state based on excessive drift of a signal from at least one of the plurality of load cells when the scale controller is in the stable state.   
     
     
         19 . The scale controller of  claim 18 , wherein the scale controller transitions between the motion state, stable state, and fault state based on predefined conditions, comprising:
 transitioning from the stable state to the motion state when an external motion signal is received indicating movement of the mobile storage or when fluctuating signals from the plurality of load cells exceed a predefined variability threshold;   transitioning from the motion state to the stable state when the external motion signal indicates that the mobile storage has stopped moving and the signals from the plurality of load cells remain stable below the predefined variability threshold for a predetermined duration;   transitioning from the stable state to the fault state when at least one of the plurality of load cells exhibits excessive drift beyond a predefined drift threshold while the scale controller is in the stable state;   transitioning from the stable state to the fault state when a sufficient number of the plurality of load cells remain stable while at least one other load cell exhibits fluctuating signals such that the number of stable load cells is greater than n/2 and less than n−1, where n represents a total number of the plurality of load cells; and   transitioning from the fault state to the stable state upon operator intervention or a system reset to clear the fault condition.